Five benchmark-gated optimizations from a fresh six-way audit (benches/ROUND25.md),
each with a BEFORE/AFTER gate that rolls back if AFTER does not beat BEFORE:
- M1 EncryptedBlobBackend::decrypt_bytes: replace split_off (a fresh Vec + full
ciphertext memcpy on every decrypted chunk, contradicting its own "in place"
doc) with in-place detached decrypt + a zero-copy Bytes::slice past the nonce.
Peak RAM per read drops from ~2x to ~1x the payload (-262KB/op at 256KiB;
scales with blob size). Plaintext byte-identical; tamper/wrong-key tests pass.
- M2 delta commit: move-unzip the owned chunk list instead of a third
per-occurrence hash clone (-4000 allocs on a 4000-chunk commit).
- M3 folder ZIP download: drop the dead Query<HashMap> extractor it never read
(byte-identical response; 5->0 allocs/request).
- Q1 public-playlist listing: fold the per-playlist COUNT(*) N+1 into one
LEFT JOIN ... GROUP BY via a new inherent repo method (101 -> 1 round-trips,
36x wall on a 100-playlist page).
- Q2 contact REST listings (paginated/search/by-group): stop over-fetching the
multi-KB vcard TEXT the ContactDto discards, via a shared lite row mapper and
narrowed SELECTs (6.4x wall on 1000 contacts with 8KiB vcards). The whole-book
vCard export and CardDAV sync paths keep the column.
Adds bench_round25_micro (counting allocator tracking count+bytes) and
bench_round25_queries (live Postgres), both with equivalence gates and a
rollback exit(1). Verified: cargo fmt clean, cargo clippy -D warnings clean,
cargo test --lib --features bench = 529 passed / 0 failed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L8gs91AhmazoxMsDcNk3KT
Claude